In conventional electric devices, as shielding material, a metal material including aluminum such as aluminum die-cast is generally used with regard to a housing, and a braided shield or a wound shield of copper wire for low frequencies and a tape shield of aluminum foil for high frequencies are widely used with regard to a cable. A shielding effect means a minus effect of shielding electromagnetic wave component, which becomes external noise, by dropping a potential to the ground with a grounded shield.
The inventor has found that, both in a battery-mounted electric device to be charged with an AC power supply and in an ordinary electric device to work with an AC power supply, an influence of inherent frequency of an AC power supply used therefor causes a problem that energy efficiency of electrons flowing in such electric device is lower, as described below.
Since conventional electric devices are sourced from an AC power supply with a single frequency, which is, for example, 50 Hz or 60 Hz in Japan, there is the problem that energy efficiency of electrons flowing in the electric device is lower. This event also occurs in a battery-mounted electric device, that is, the same problem that energy efficiency of electrons recorded in the battery is lower is caused, being affected by the influence of a single frequency of an AC power supply at the time of charging an original battery.
Conventionally, it has been thought that electrons are definitely homogeneous in their own level and a concept of differences in quality of electrons does not exist.